Cod sursa(job #967143)

Utilizator andrettiAndretti Naiden andretti Data 27 iunie 2013 11:10:47
Problema Poligon Scor 50
Compilator cpp Status done
Runda Arhiva de probleme Marime 1.76 kb
#include<stdio.h>
#include<algorithm>
#define maxn 805
#define maxm 60005
using namespace std;

struct point{double x,y;};
point v[maxn],p[maxm];

int n,m,sol;
int inter;

void cit()
{
    int i;
    scanf("%d%d",&n,&m);
    for(i=1;i<=n;i++) scanf("%lf%lf",&v[i].x,&v[i].y);
    for(i=1;i<=m;i++) scanf("%lf%lf",&p[i].x,&p[i].y);
    v[0]=v[n]; v[n+1]=v[1];
}

int between_o(point a,point b,point c)
{
    if(b.x<a.x && c.x>a.x) return 1;
    if(b.x>a.x && c.x<a.x) return 1;
    return 0;
}

int between_v(point a,point b,point c)
{
    if(b.x==a.x && c.x==a.x)
    {
        if(b.y>a.y && c.y<a.y) return 1;
        if(b.y<a.y && c.y>a.y) return 1;
    }
    return 0;
}

double intersect(point a,point b,double xx)
{
    return (xx-a.x)*(b.y-a.y)/(b.x-a.x)+a.y;
}

double side(point a,point b,point c)
{
    return (c.x-a.x)*(b.y-a.y)-(c.y-a.y)*(b.x-a.x);
}

int search(int k)
{
    int i;
    double yc;
    point aux=p[k];
    aux.y=aux.y+1;

    inter=0;
    for(i=1;i<=n;i++)
    {
        if(between_o(p[k],v[i],v[i+1]))
        {
            yc=intersect(v[i],v[i+1],p[k].x);
            if(yc==p[k].y) return 1;
            else
             if(yc<p[k].y) inter++;
        }

        if(v[i].x==p[k].x && v[i].y==p[k].y) return 1;

        if(between_v(p[k],v[i],v[i+1])) return 1;
        if(v[i].x==p[k].x && v[i].y<p[k].y && side(p[k],aux,v[i-1])*side(p[k],aux,v[i+1])<0) inter++;
    }

    if(inter%2==1) return 1;
    return 0;

}

void solve()
{
    int i;
    for(i=1;i<=m;i++) sol+=search(i);
}

int main()
{
    freopen("poligon.in","r",stdin);
    freopen("poligon.out","w",stdout);

    cit();
    solve();
    printf("%d",sol);

    fclose(stdin);
    fclose(stdout);
    return 0;
}